I have a very old window probably from the beginning of this house in 1970's. Now I want to replace this old aluminum window with a bow window. my question is there are two posts of the triple window. Are they structural elements? Are they part of this triple window or the builder added them there to fit the aluminum double hungs?
The whole opening is as big as 120" X 56 3/4" I wonder the reason they put it there when they built this house. The window frame gave some support?